橡胶土减载深覆土明洞受力特性研究

Research on Stress Characteristics of Deep Covered Open Tunnels with Rubber Soil Load Reduction

摘要:

随着国家“西部大开发”、“一带一路”等发展战略的深入实施，我国西部地区交通基础设施建设迅速发展，城市中增加了许多深覆土基础设施，深覆土明洞因隧道顶部覆土厚度过大，容易出现结构开裂、衬砌掉块等影响隧道安全运营的问题，因此，采取有效减载措施，减小深覆土明洞工程中隧道结构周围土压力，对于确保隧道结构的安全稳定十分重要。结合九安隧道大厚度回填明洞工程，利用有限差分程序FLAC3D建立了三维数值仿真模型，研究了无减载和橡胶土减载两种工况下回填土中土压力以及隧道结构内力变化，在隧道顶部铺设橡胶土，可有效减小衬砌结构内力，有利于隧道明洞衬砌结构安全，同时也为废旧橡胶固废利用提供了一种途径。

Abstract:

With the in-depth implementation of national development strategies such as the "Great Western Development" and the "Belt and Road", the transportation infrastructure construction in western China has developed rapidly, and many deep-covered soil infrastructures have been added in cities. Deep-covered soil open tunnels are prone to structural cracking, lining falling blocks and other problems affecting the safe operation of tunnels due to the excessive thickness of soil cover at the top of tunnels. Therefore, it is very important to take the effective load reduction measures and reduce the soil pressure around the tunnel structure to ensure the safety and stability of the tunnel structure in the deep covered open tunnel projects. Combined with the large-thickness backfill open tunnel project of Jiuan Tunnel, a three-dimensional numerical simulation model is established by using the finite difference program FLAC3D to study the changes of soil pressure and tunnel structural internal force in the backfill soil under two construction conditions of no load reduction and rubber soil load reduction. Laying the rubber soil on the top of the tunnel can effectively reduce the internal force of the lining structure, which is conducive to the safety of the open tunnel lining structure. At the same time, a way for the utilization of waste rubber solid waste is provided.